1. Field of the Invention
The present invention relates to a connector for connecting a dialysate port of a dialyzer to a dialysate-carrying line with a first lumen and a second lumen passing through the connector, a first end of the connector surrounding the first lumen, suitable for accommodating the dialysate port in the first lumen, a second end of the connector surrounding the second lumen and suitable for being connected to the dialysate-carrying line.
2. Description of Related Art
During a hemodialysis treatment, blood is taken from a patient with the help of an extracorporeal circulation and is passed through a dialyzer. Such dialyzers today consist of a bundle of thousands of semipermeable hollow fiber membranes through the interior of which the blood is passed. A cleaning fluid—the dialysis fluid or the dialysate—is circulated on the outside of the hollow fibers so that the substances to be removed from the blood enter this fluid by diffusion and/or convection.
Such a dialyzer generally has four liquid connections, which are known as ports: two for blood and two for the dialysate. The tubing system of the extracorporeal blood circulation and the dialysate-carrying line system in the sense of one incoming line and one-outgoing line is connected to these ports. For the purpose of uniformity in use, standardized port forms are used for the blood ports on the one hand and for the dialysate ports on the other hand. Although the connecting system for the blood tubing system is designed to work with disposable items, the tubing used for the lines carrying the dialysate with many dialyzers for treatment of chronic renal insufficiency is reusable. The Hansen coupling, as it is called, is used as the connecting system. With the Hansen coupling, the connection to the dialysate port is locked by a metallic ball bearing element. According to DIN 58352, a German standard, the dialysate port consists of an essentially tubular projection having a peripheral undercut upstream from the end of the port in the sense of a reduced outside diameter in which the balls of the ball bearing element engage. Between individual treatments, the dialysate-carrying lines are rinsed and cleaned together with the remaining dialysate circulation.
However, with other dialyzers, disposable tube sets are also used for the dialysate-carrying lines. In this case it is expedient to use a design different from the Hansen coupling for the corresponding connector, in particular when the connector is also a disposable part.
EP 0 442 310 A1 describes dialyzer ports of a dialyzer which allow connection of Hansen couplings as well as other connectors. To this end, the dialyzer port is provided with a thread onto which a corresponding connector mating piece can be screwed.
A screwing motion to establish the connection is a disadvantage inasmuch as it is difficult to determine the endpoint of the screwing motion. Leakage may occur if the connector is not screwed on adequately, while on the other hand, if too much force is applied to the end of the connector, it may quickly result in damage to the sealing elements, which are generally provided in these connectors. In addition, this connector may be used only when the ports on the dialyzers are also designed accordingly, i.e., design measures are also required on the mating piece of the connector.